This invention relates to insulating of electrical coils and more specifically to insulating stator motor coils with a void free, impermeable, and symmetrical electrical insulation barrier.
During the insulating of stator motor coils, it has been long sought to devise a procedure which would produce a uniform electrical insulation barrier for stator motor coils including the lead points of the coils. Conventional practice has largely been the problematic manual application of such insulation. However, severe performance requirements for Naval motors intended for operation under stringent environmental conditions such as high temperature and high hydrostatic pressures have increased the need for better insulation and procedures for applying the insulation to the coils. Investigation of a recently developed, commercially available, molded insulation system revealed that by that system the insulation was applied and molded on the coil wires while they were retained in a flat, elliptical shape. The flat molded coils were later removed from the mold and then mechanically spread and formed into the proper stator coil configuration to facilitate insertion into the intended electrical motor. Although a uniform thickness of insulation was provided around the coil wires, harmful stresses produced on the insulation during the final spreading and shaping process, and poor insulation bonding to the coil wires adversely affected the electrical properties of the coils and left a need for a better method of insulation application to stator coils.